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Path: utzoo!utgpu!lharris
From: lharris@gpu.utcs.utoronto.ca (Leonard Harris)
Date: Fri, 23-Jun-89 02:10:28 EDT
Message-ID: <1989Jun23.021028.8476@gpu.utcs.utoronto.ca>
Organization: University of Toronto Computing Services
Newsgroups: comp.sys.atari.st
Subject: Re: EZRAM II info needed
References: <8906220244.AA08485@cunixa.cc.columbia.edu> <645@lzaz.ATT.COM> <8755@chinet.chi.il.us>
Reply-To: lharris@gpu.utcs.UUCP (Leonard Harris)

In article <8755@chinet.chi.il.us> saj@chinet.chi.il.us (Stephen Jacobs) writes:
>In article <645@lzaz.ATT.COM>, hcj@lzaz.ATT.COM (HC Johnson) writes:
>> In article <8906220244.AA08485@cunixa.cc.columbia.edu>, cmm1@CUNIXA.CC.COLUMBIA.EDU (Christopher M Mauritz) writes:
>> > 
>> > I've been offered a brand new EZRAM II board with 2 megs of brand new 120ns
>> > 1mbit DRAMs for $285.  Is this a good price?  I seem to remember several
>.......................................................................
>> However, for a 2 meg upgrade you should use the 100 ns drams.
>> 
>> Howard C. Johnson
>> ATT Bell Labs
>> att!lzaz!hcj
>> hcj@lzaz.att.com
>[The above is heavily edited, of course]
>
>I'd like to hear more about this.  On paper, 120 ns DRAM is just right for
>the ST design, and people tell me that ST-s work just fine with selected units
>of nominally 150 ns DRAM.  What makes faster memory parts more desirable in
>larger configurations?  (This is taking the Atari custom chips as a given, so
>there's no option of speeding up the system clock).  And that price sure sounds
>good: board + chips for the price of the chips.
>                                      Steve J.

The reason for using faster 1 meg rams is that their quality is higher.  
Early masks of toshiba 1 meg drams were very prone to noise - the 100 and
80 ns parts were more immune.  The st doesn't need anything faster
than 150ns.  If the memory board is properly designed then slow
parts should work just fine.
/leonard

